Lyndex-Nikken CAT40-SK20-90UP Collet Chucks; Collet System: Slim Chuck ; Collet Series: SK20 ; Taper Size: CAT40 ; Projection (Decimal Inch): 3.5400in ; Minimum Collet Capacity (Decimal Inch): 0.1380in ; Maximum Collet Capacity (Decimal Inch): 0.7870